Evacuating coupling



July 17, 1962 M. DREWES, JR 3,0 4, 7

EVACUATING COUPLING Filed June 16, 1961 United States Patent Ofifice3,044,275 Patented July 17, 1962 3,044,275 EVACUATIN G COUPLING MenkeDrewes, Jr., Highland Park, Ill., assignor, by mesne assignments, toMartin-Marietta Corporation, Chicago, 111., a corporation of Maryland'2' Filed June 16, 1961, Ser. No. 117,558 6 Claims. (Cl. 62-268) Thepresentinvention relates generally to evacuating apparatus and moreparticularly to a coupling for use in evacuating the interior of ahollow, space environmentsimulating test body to a pressurecorresponding to that existing in outer space.

Currently, there is considerable interest in space vehicles, lunarprobes, and interplanetary travel, and in the development of suit-abletest facilities capable of simulating lunar-space environments. Thepresent inventors application Serial No. 91,859, filed February 24,1961, describes a space-simulating facility within which are maintainedlight, temperature, and pressure conditions corresponding to thoseexisting in outer space. The evacuating coupling of the presentinvention is used in conjunction with the space-simulating test bodydescribed in this prior application, and facilitates a reduction of thepressure in this body to the pressure level in outer space (e.g. l 10mm. Hg).

Essentially, the subject coupling comprises a housing having inlet meansin communication with the interior of the space-simulating body, andoutlet means in communication with an evacuating pump. Within thehousing are means, subsequently to be described in greater detail, foraccumulating gases condensable at the temperature existing within thetest body, e.g. 70 to 120 K. Accordingly, although virtually all thegases within the test body are drawn into the coupling, only those gaseswhich are non-condensable under the test conditions are withdrawn fromthe coupling. Thus the load on the evacuating pump is substantially lessthan what it would wherein:

FIGURE 1 is a vertical sectional view showing an evacuating couplingconstructed in accordance with th present invention;

FIGURE 2 is a sectional view taken along line 2-2 in FIGURE 1.

Referring to the drawings,numeral 11 indicates generally an evacuatingcoupling constructed in accordance with the present invention. Coupling11 is in the form of a housing having a first conduit portion or inletmeans 14 terminating at a flange 13 secured to another flange 27surrounding a port 31 in the wall of a hollow spacesimulating test bodyindicated generally at 12. Integral with first conduit portion 14 is amain body portion 15 integral with a second conduit portion or outletmeans 16 terminating at a flange 28 secured to a flange 29 on a conduit30 leading to an evacuating pump (not shown). Within housing mainportion 15 is a hollow, disk-shaped, fluid cooled baflle 17, and aroundthe periphery of baffle 17 is an annular opening indicated generally at.18. Located between opening 18 and inlet means 14 is a hollow,doughnut-shaped, fluid-cooled gas-condensing or accumulating element 19.Located between annular opening 18 and outlet means 16 is a secondhollow, doughnutshaped, fluid-cooled condensing element 20.

Baflie 17 and doughnut-shaped elements 19, 20 are cooled with a cryogensuch as liquid nitrogen. The temperatures of these cryogen-cooledelements and of the interior of the test body 12 are on the order of 70to 120 K.' At'these temperatures, gaseous molecules tend to rebound likebilliard balls in response to impingement 5 against a surface. When theevacuating pump is operating gas molecules are withdrawn from theinterior of test body 12, pass through inlet means 14, strike baflie 17and are initially deflectedback and forth between baflle 17 anddoughnut-shaped condensing element 19. Gases such as water vapor, carbondioxide, and others which are condensable at the temperatures existingin the coupling tend to deposit or accumulate on baflle 17 anddoughnutsha-ped element 19.

That portion of the gas which does not deposit on these elementseventually is drawn around bafile 17 through the peripheral annularopening 18, whereupon gaseous molecules strike and are deflected bydoughnut-shaped element 20, located between annular opening 18 andoutlet conduit 16. As the molecules are deflected back and forth betweenbaffle 17 and element 20 that portion of the gas passing through opening18 which is condensable will tend to deposit on bafile 17 as well as onelement 20. The only portion finally withdrawn through outlet conduit 16is made up almost entirely of non-condensable types, such as hydrogen,helium, neon, and the like. Therefore, only a portion of the gaswithdrawn through opening 31 of test body 12 passes through the outletmeans 16 of the evacuating coupling. Accordingly, the load on theevacuating pump is substantially less than that required if anevacuating coupling constructed in accordance with the present inventionwere not interposed between the pump and the test body.

Cryogen is circulated through doughnut-shaped elements 19, 20 by inletconduits 21, 22 respectively and outlet conduits 23, 24 respectively.Cryogen is circulated through hollow disk-shaped element 17, throughinlet conduit 25 and outlet conduit 26.

The foregoing detailed description has been given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, as modifications will be obvious to those skilled in the art.

What is claimed is:

1. An evacuating coupling comprising:

a housing having inlet means for connection to the interior of abody-to-be-evacu-ated, and outlet means for connection to an evacuatingpump;

fluid-cooled bafile means within said housing between said inlet meansand said outlet means;

3. A coupling as recited in claim 2 and comprising:

means on each of said hollow, doughnut-shaped elements for introducingliquid cryogen thereinto; and means on each of the doughnut-shapedelements for draining said liquid cryogen therefrom.

4. A coupling as recited in claim 1 wherein said baffle means comprises:

a hollow disc-shaped element; means for introducing liquid cryogen intosaid hollow disc-shaped element; and means for draining said liquidcryogen from the disc-shaped element.

an annular opening around the periphery of said bafile -5. A couplingfor use in evacuating the interior of a space-simulating hollow body toa pressure corresponding to that existing in outer space, said couplingcomprising: o p I V a housing having inlet fmeans for connection to theinterior of said body and outlet means for connection to an evacuatingpump; V

cryogen-cooled bafiie means within said housing betw eensaid inlet meansand said outlet means;

7 an annular opening around the peripheryof said 'baffle and' hollow,doughnut-shaped, cryogenwcooled con- References Cited in the file ofthis patent UNITED STATES PATENTS Hippie Mar. 22, 1949 Smith -Q June 27,1950 Dowley et a1. Aug. 28, 1951 Penn Mar. 22, 1961

